Inspection apparatus, method of controlling the same, printing system, and program

Abstract

To solve such problems that a screening apparatus for inspecting a defect and failure of a printed matter and an inspection apparatus for inspecting quality of characters are required when executing a screening process of inspecting the defect and failure of the printed matter and an inspection process of inspecting the quality of the characters, and control of a system is complicated.SOLUTION: An inspection apparatus operable to inspect a printed matter is provided. The inspection apparatus, in a case where a screening process for inspecting a defect of the printed matter is set, performs a screening process on the image data to be inspected, which has been obtained by reading the printed matter by reading means, based on a reference image, and in a case where a character quality inspection process for inspecting a quality of a character of the printed matter is set, performs a character quality inspection process on the image data to be inspected, which has been obtained by reading the printed matter by the reading means, based on the reference image. The inspection apparatus makes an instruction so as to adjust image data to be printed by a printing apparatus that generated the printed matter in accordance with an inspection result of the character quality inspection process.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an inspection device, a control method thereof, a printing system, and a program. [Background technology]

[0002] Conventionally, there are inspection systems that check whether printed matter produced by a printing and binding system has any defects or imperfections. There are also automatic character image quality adjustment systems that inspect the image quality of printed matter produced by a printing and binding system to check whether the characters are illegible, and then automatically adjust the printing and binding system according to the inspection results.

[0003] Patent Document 1 describes an inspection device that compares a reference image for inspection with a printed image obtained by reading a printed material output from a printing device with a reading device such as a scanner. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-101015 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the above-mentioned conventional inspection device does not describe the inspection of the quality of characters on printed matter, etc. Therefore, when performing an inspection process to inspect printed matter for abnormalities and defects and an inspection process to inspect character quality, an inspection device for inspecting printed matter for abnormalities and defects and an inspection device for inspecting character quality are required, respectively, which increases the scale of the entire system. Furthermore, when such an inspection device and an inspection device are provided, the printed matter is read by a scanner of each device, making system control complicated.

[0006] An object of the present invention is to solve at least one of the problems of the prior art.

[0007] The object of the present invention is to solve the above problem by enabling a single inspection device to perform an inspection process that inspects printed matter for abnormalities and defects, and an inspection process that inspects character quality. [Means for solving the problem]

[0008] In order to achieve the above object, an inspection device according to one aspect of the present invention has the following configuration: An inspection device for inspecting printed matter, a reading means for reading a printed matter and acquiring image data of an object to be inspected; an inspection means for performing inspection processing of the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when an inspection processing for inspecting abnormalities in the printed matter is set; a character quality inspection means for performing character quality inspection processing of the image data to be inspected, which is obtained by reading the printed matter with the reading means, based on a reference image, when a character quality inspection processing for inspecting the quality of characters on the printed matter is set; and an instruction means for instructing the printing device that generated the printed matter to adjust image data to be printed in accordance with the inspection result by the character quality inspection means. [Effects of the Invention]

[0009] According to the present invention, a single inspection device can perform both an inspection process to check for abnormalities and defects in printed matter and an inspection process to check the quality of characters, which has the effect of not complicating system control and reducing the burden on users on settings and work.

[0010] Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which the same or similar elements are designated by the same reference numerals. [Brief explanation of the drawings]

[0011] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. [Figure 1] FIG. 1 is a diagram showing an example of a network configuration including a printing system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram illustrating the hardware configuration of a printing device, an external controller, an inspection device, and a client PC in the printing system according to the first embodiment. [Figure 3] 5 is a flowchart illustrating a processing flow in the printing system according to the first embodiment. [Figure 4] FIG. 1A shows an example of a screen for setting the inspection process and automatic adjustment of character quality, which is displayed on the display unit of the inspection device of embodiment 1, and FIG. 1B shows an example of a screen for making various settings for the inspection process when the inspection process is selected. [Figure 5] FIG. 1A shows an example of a character quality inspection setting screen displayed on the display unit of the inspection device of embodiment 1, and FIG. 1B shows an example of a screen when each item of the character quality inspection setting is set to automatic in embodiment 2. [Figure 6] FIG. 4 is a diagram illustrating an example of print data (printed matter) printed on paper according to settings in the first embodiment. [Figure 7] FIG. 7 is a diagram showing an example of a PDL data PDF description of the printed matter of FIG. 6. [Figure 8] FIG. 10 is a diagram showing an example of an image obtained by cutting out a character portion from a reference image. [Figure 9] 1A shows an example of an image in which a character portion is extracted from image data of an object to be inspected, and FIG. 1B shows an example of an image in which the extracted character portion has been corrected. [Figure 10] Schematic diagram for explaining quantification of character image quality. [Figure 11] FIG. 10 is a diagram showing an example of a table showing the relationship between the character thickness degree α and the adjustment level Lc. [Figure 12] 5A to 5C are diagrams for explaining adjustment control of character quality by an image processing unit of the printing device according to the first embodiment. [Figure 13] 6 is a flowchart for explaining a coordinate analysis process of a character portion executed by an external controller according to the first embodiment. [Figure 14] 10 is a flowchart illustrating the flow of processing in a printing system according to a second embodiment. [Figure 15] 11 is a flowchart illustrating the flow of a process for setting and registering a font for image quality inspection by an external controller of a printing system according to a third embodiment. [Figure 16] FIG. 11 is a diagram showing an example of development of a character font according to the third embodiment. [Figure 17] FIG. 10 is a diagram showing an example of an image obtained by applying binarization processing to image data that has been subjected to anti-aliasing processing. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0013] [Embodiment 1] FIG. 1 is a diagram showing an example of a network configuration including a printing system 101 according to a first embodiment of the present invention.

[0014] The printing system 101 is connected to an external controller 102 (information processing device). The printing system 101 and the external controller 102 constitute an image processing system. The printing system 101 may also be called, for example, an image forming apparatus, a multifunction peripheral, or a multifunction peripheral (MFP). The printing system 101 and the external controller 102 are communicatively connected via an internal LAN 105 and a video cable 106. The external controller 102 is communicatively connected to a client PC 103 via an external LAN 104. The external controller 102 may also be called, for example, an image processing controller, a digital front end (DFE), or a print server.

[0015] The client PC 103 can issue a print instruction to the external controller 102 via the external LAN 104. A printer driver is installed on the client PC 103. This printer driver has the function of converting print data into data in a Page Description Language (PDL) that can be processed by the external controller 102. By operating the client PC 103, a user can issue a print instruction to the printing system 101 via the printer driver from various applications installed on the PC 103. The printer driver transmits print data, i.e., PDL data, to the external controller 102 based on the print instruction from the user. Upon receiving PDL data from the client PC 103, the external controller 102 analyzes and interprets the received PDL data. Then, based on the results of this interpretation, the external controller 102 performs a rasterization process to generate bitmap image data with a resolution matching the print system 101, and inputs this data to the print system 101 to issue a print instruction. The resolution is typically 600 dpi, with many high-resolution printing systems using 1200 dpi. The following explanation uses an example of a resolution of 600 dpi.

[0016] The printing system 101 includes a plurality of devices each having different functions, and is configured to be able to perform various processes such as bookbinding. In the first embodiment, the printing system 101 includes a printing device 107, an inserter 108, an inspection device 109, a large-capacity stacker 110, and a finisher 111. An image is printed by the printing device 107, and sheets (paper) ejected from the printing device 107 are transported through the inserter 108, the inspection device 109, the large-capacity stacker 110, and the finisher 111 in this order. In the first embodiment, the printing system 101 is an example of an image forming device, but the printing device 107 included in the printing system 101 may also be referred to as an image forming device, a multifunction device, or a multifunction peripheral (MFP). In addition, this inspection device 109 not only inspects the presence or absence of stains, color misalignment, or misalignment of the print, but also inspects the quality of the characters on the print, including the presence or absence of blurred or crushed characters, and can perform the character adjustment function described below based on the results.

[0017] The printing device 107 forms (prints) an image on a sheet fed and transported from a paper feed unit disposed below the printing device 107 using toner (developer). The inserter 108 inserts a sheet into a series of sheets transported from the printing device 107. The inspection device 109 has a function of inspecting printed matter and a function of adjusting characters. The inspection function is a function for inspecting the transported sheet on which an image has been printed by the printing device 107, as the sheet is transported through a transport path. More specifically, the inspection function is a function for inspecting the image printed on the transported sheet (determining whether the image is normal or not) by reading the image printed on the transported sheet and comparing the obtained image data with a pre-registered reference image.

[0018] On the other hand, the character adjustment function adjusts the image quality of the characters on a sheet conveyed through a conveyance path, on which an image has been printed by the printing device 107, to a more appropriate level of reproducibility. More specifically, the character adjustment function comprises an inspection function and an adjustment function. The inspection function reads the image printed on the conveyed sheet and compares the resulting image data with a reference image, which is bitmap image data obtained by rasterizing PDL data. This comparison inspects the reproducibility of the characters printed on the sheet (determines blurred or crushed images, etc.). If blurred or crushed characters are found as a result of this inspection, the function instructs the printing device 107 to adjust image processing settings and process settings to achieve a more appropriate level of image quality for the reproducibility of the characters. The large-capacity stacker 110 is a device capable of stacking a large number of sheets. The finisher 111 is a device capable of performing finishing processes, such as stapling, punching, and saddle-stitching, on the conveyed sheets. After processing by the finisher 111, the sheets are discharged to a specified paper output tray.

[0019] FIG. 2 is a block diagram illustrating the hardware configuration of the printing device 107, the external controller 102, the inspection device 109, and the client PC 103 of the printing system 101 according to the first embodiment.

[0020] The printing device 107 includes a communication I / F (interface) 217, a network I / F 218, a video I / F 220, a HDD 221, a CPU 222, a memory 223, and a UI display unit 225. The printing device 107 further includes an image processing unit 224 and a print unit (printer engine) 226. These are connected to each other via a system bus 213.

[0021] The communication I / F 217 is connected to the inserter 108, the inspection device 109, the large-capacity stacker 110, and the finisher 111 via a communication cable 260. The CPU 222 communicates with each device via the communication I / F 217. The network I / F 218 is connected to the external controller 102 via the internal LAN 105 and is used for communicating control data and the like. The video I / F 220 is connected to the external controller 102 via a video cable 106 and is used for communicating data such as image data. The video I / F 220 is also connected to the video I / F 244 of the inspection device 109 via a video cable 245. Note that the printing device 107 (printing system 101) and the external controller 102 may be connected only by the video cable 106, as long as the external controller 102 can control the operation of the printing system 101.

[0022] Various programs and data are stored in the HDD 221. The CPU 222 controls the operation of the printing device 107 by loading the programs stored in the HDD 221 into the memory 223 and executing them. The memory 223 stores programs and data required for the CPU 222 to perform various processes. The memory 223 also operates as a work area for the CPU 222. The UI display unit 225 accepts various setting inputs and operation instructions from the user and is used to display various information such as setting information and the processing status of print jobs.

[0023] The image processing unit 224 converts the bitmap image data generated by the external controller 102 into image data that is optimal for the printing system. For example, if the data is color data, it performs color conversion processing to optimally convert the color, and if the data is text, it performs character adjustment processing (thin line thickness adjustment processing) to optimally convert thin lines. More specifically, in a certain printing system, if the thin black lines of the text are faint, it performs character adjustment processing (thin line thickness adjustment processing) to thicken the thin black lines in advance, and prints appropriate thin black lines. Also, if the thin white lines surrounded by thin black lines are crushed, it performs character adjustment processing (thin line thickness adjustment processing) to thin the thin black lines in advance, and prints appropriate thin black lines. Details of the character adjustment processing will be described later.

[0024] The print unit 226 forms (prints) an image using toner (developer) on a sheet fed and transported from a paper feed unit located below the printing device 107, based on print data converted into a bitmap optimal for printing by the image processing unit 224.

[0025] The inserter 108 feeds sheets to be inserted from a paper feed unit of the inserter 108 and controls the conveyance of sheets conveyed from the printing device 107 .

[0026] The inspection device 109 includes a communication I / F 237, a CPU 238, a memory 239, an image reading unit 240, a display unit 241, an operation unit 242, a HDD 255, and a video I / F 244. These devices are connected to one another via a system bus 243. The communication I / F 237 is connected to the printing device 107 via a communication cable 260. The CPU 238 performs communication necessary for controlling the inspection device 109 via the communication I / F 237. The CPU 238 controls the operation of the inspection device 109 by executing a control program stored in the memory 239. The control program for the inspection device 109 is stored in the memory 239.

[0027] The image reading unit 240 reads the conveyed sheet in accordance with instructions from the CPU 238. The CPU 238 stores the image data obtained by reading the image of the sheet with the image reading unit 240 in the memory 239 as a reference image for inspection. The CPU 238 further compares the image data of the inspection target read by the image reading unit 240 with the reference image stored in the memory 239, and performs an inspection process to inspect the image printed on the sheet based on the comparison result. The CPU 238 also inspects the reproducibility of the characters printed on the sheet by comparing bitmap image data obtained by rasterizing the PDL data as a reference image for the characters with the image data of the inspection target used in the inspection process described above. Then, it performs a character quality adjustment process to determine the amount of character adjustment based on the inspection result. The determined amount of character quality adjustment is sent to the printing device 107 and set in the thin line thickness adjustment process of the image processing unit 224, so that thin lines are printed with an optimal thickness. Although the image data obtained by the image reading unit 240 is used as the reference image for the inspection process, bitmap image data obtained by rasterizing PDL data may also be used, as with the reference image for inspecting character quality.

[0028] The display unit 241 is used to display the results of the inspection process, the results of character quality adjustment, setting screens, etc. The operation unit 242 is operated by the user and accepts various instructions from the user (for example, changing the settings of the inspection device 109, instructions to register a reference image for the inspection process, specification of the character type and size to be inspected, etc.). The HDD 255 stores various setting information and image data required for the inspection process, character quality inspection process, and character quality adjustment. The various setting information and image data stored in the HDD 255 can be reused. The video I / F 244 is connected to the video I / F 220 of the printing device 107 via a video cable 245, and is used to send and receive image data (print data).

[0029] The stacker 110 controls the sheet conveyed along the conveying path so that the sheet is discharged to a stack tray, discharged to an escape tray, or conveyed to a finisher 111 connected downstream in the sheet conveying direction.

[0030] The finisher 111 controls the transport and discharge of sheets, and performs finishing processes such as stapling, punching, or saddle stitching.

[0031] The external controller 102 includes a CPU 208, a memory 209, a HDD 210, a keyboard 211, a display unit 212, network I / Fs 213 and 214, and a video I / F 215. These devices are connected to one another via a system bus 216. The CPU 208 controls the operation of the external controller 102 by loading a program stored in the HDD 210 into the memory 209 and executing it. For example, the CPU 208 receives PDL data from the client PC 103, performs RIP processing to rasterize the PDL data, and transmits print data to the printing system 101. The memory 209 stores programs and data required for the CPU 208 to perform various processes. The memory 209 also functions as a work area for the CPU 208.

[0032] The HDD 210 stores various programs and data. The keyboard 211 is used for inputting operation instructions for the external controller 102 from the user. The display unit 212 is used, for example, to display information about applications currently running on the external controller 102 and an operation screen. The network I / F 213 is connected to the client PC 103 via the external LAN 104 and is used for communicating data such as print instructions. The network I / F 214 is connected to the printing device 107 via the internal LAN 105 and is used for communicating data such as print instructions. The video I / F 215 is connected to the printing device 107 via the video cable 106 and is used for communicating data such as image data (print data).

[0033] The client PC 103 includes a CPU 201, a memory 202, a HDD 203, a keyboard 204, a display unit 205, and a network I / F 206. These devices are connected to one another via a system bus 207. The CPU 201 controls the operation of each device via the system bus 207 by loading a program stored in the HDD 203 into the memory 202 and executing it. This allows the client PC 103 to perform various processes. For example, the CPU 201 loads a document processing program stored in the HDD 203 into the memory 202 and executes it, thereby generating print data and issuing a print instruction. The memory 202 stores programs and data required for the CPU 201 to perform various processes. The memory 202 also functions as a work area for the CPU 201.

[0034] The HDD 203 stores various applications (e.g., word processing programs), programs such as printer drivers, and various data. The keyboard 204 is used for inputting operation instructions for the client PC 103 from the user. The display unit 205 is used for displaying, for example, information about applications currently running on the client PC 103 and an operation screen. The network I / F 206 is communicably connected to the external controller 102 via the external LAN 104. The CPU 201 communicates with the external controller 102 via the network I / F 206.

[0035] 1, the external controller 102 is connected to the printing system 101, but the present invention can also be applied to a different configuration. For example, the printing system 101 may be connected to an external LAN 104, and print data may be sent from the client PC 103 to the printing system 101 without going through the external controller 102. In this case, data analysis, interpretation, and rasterization of the print data are performed by the printing system 101.

[0036] FIG. 3 is a flowchart for explaining the processing flow in the printing system 101 according to the embodiment. In this flowchart, the processing of the inspection device 109 is realized by the CPU 238 executing the program developed in the memory 239, and the processing of the external controller 102 is realized by the CPU 210 executing the program developed in the memory 209.

[0037] First, at S301, the CPU 238 of the inspection device 109 displays on the display unit 241 the inspection product and character quality adjustment setting screen shown in FIG. 4(A), and the user makes a setting as to whether to execute either the inspection product process or the automatic adjustment of the character quality.

[0038] FIG. 4(A) is a diagram showing an example of a screen for setting the inspection product process and the automatic adjustment of the character quality displayed on the display unit 241 of the inspection device 109 according to Embodiment 1.

[0039] When the inspection product process 401 indicating the inspection product process is set to on here, the CPU 238 displays on the display unit 241 the inspection product setting screen shown in FIG. 4(B) and prompts the user to make settings for the inspection product process for inspecting abnormalities in the printed matter.

[0040] FIG. 4(B) is a diagram showing an example of a screen for making various settings for the inspection product process displayed on the display unit 241 of the inspection device 109 according to Embodiment 1. Here, the resolution (here 150 dpi) and the number of feature points can be set.

[0041] On the other hand, when the character quality adjustment 402 is set to on on the screen of FIG. 4(A), the CPU 238 displays on the display unit 241 the character quality inspection setting screen of FIG. 5(A) and prompts the user to make settings for the character quality inspection.

[0042] FIG. 5(A) is a diagram showing an example of a screen for setting the character quality inspection displayed on the display unit 241 of the inspection device 109 according to Embodiment 1. Here, the resolution (here 600 dpi), font type, font size (here 7 points or less), and font (character specification, here the Chinese character "情") are included.

[0043] The content set in this S301 is stored in the memory 239 of the inspection device 109 and is also transmitted to the external controller 102 via the printing device 107 and stored in the memory 209 of the external controller 102.

[0044] Next, proceed to S302. The PC 103 and the external controller 102 issue a print instruction to start the printing operation. Here, for the sake of simplicity, the PDL data is, for example, as shown in FIG. 8, PDF (Portable Document Format) data that prints one character (the Chinese character "情") per page. The following description will be given using an example where this PDF data is directly printed to the external controller 102.

[0045] Next, in S303, the CPU 208 of the external controller 102 performs PDL interpretation for generating a printing bitmap image, such as the font type, size, and designated character drawing position of the character, based on the above-mentioned PDF file.

[0046] Next, proceed to S304. The CPU 208 of the external controller 102 determines whether the character quality adjustment 402 was set to on in S301. If the character quality adjustment 402 is set to on here, proceed to S305. Otherwise, skip S305 and proceed to S306. In S305, the CPU 208 analyzes the coordinates of the character part based on the analysis result of the PDL analyzed in S303 and the character quality inspection setting in FIG. 5(A), and obtains the coordinates of the character part for cutting out the character image for character quality inspection from the printing image data. The details of this coordinate analysis of the character part will be described later.

[0047] Next, the process proceeds to S306, where the CPU 208 rasterizes the image data into bitmap image data according to the resolution specified in the print command. Here, the resolution is assumed to be 600 dpi, for example. The CPU 208 then sends the rasterized bitmap image data to the printing device 107 as image data to be printed, and temporarily stores the bitmap image data in the HDD 210 of the external controller 102 as a reference image. The process proceeds to S307, where the CPU 208 of the external controller 102 transfers the bitmap image data stored in the HDD 210 of the external controller 102 to the printing device 107 for printing. The transferred bitmap image data is subjected to image processing in the image processing unit 224 under the control of the CPU 222 of the printing device 107, and is then printed by the print unit 226.

[0048] Next, the process proceeds to S308, where the CPU 238 of the inspection device 109 determines whether the inspection process 401 was turned on in S301. If the inspection process 401 was turned on, the process proceeds to S310, and if not, the process proceeds to S309. In S309, the CPU 238 determines whether the character quality adjustment 402 was set on in S301. If the character quality adjustment 402 was set on, the process proceeds to S310, and if the character quality adjustment 402 was not set on, the process proceeds to S323 because there is no need to inspect the printed matter.

[0049] In S310, the CPU 238 of the inspection device 109 reads the printout printed in S307 using the image reading unit 240, and temporarily stores the image data obtained by reading in the HDD 255 as image data to be inspected for inspection processing, character quality inspection, or both. At this time, the resolution at which the image reading unit 240 reads the printout printed in S307 is the resolution specified in the character quality inspection settings in Fig. 5(A) or the highest resolution at which the image reading unit 240 can read, so that fine details of the characters can be read. Here, the description will be given assuming that reading is performed at the resolution (600 dpi) specified in the character quality inspection settings in Fig. 5(A).

[0050] Next, the process proceeds to S311, in which the CPU 238 of the inspection device 109 acquires the bitmap image data used during printing from the printing device 107 via the video cable 245, and stores the image data in the HDD 255 as a reference image for the inspection process, character quality inspection, or both.

[0051] Next, the process proceeds to S312, where the CPU 238 of the inspection device 109 determines whether the inspection process 401 is set to ON. If the inspection process is set to ON, the process proceeds to S313; if not, the process proceeds to S317. In S313, the CPU 238 performs resolution conversion to reduce the 600 dpi inspection target image data acquired in S310 and the 600 dpi reference image acquired in S311 to 150 dpi, which is the resolution for the inspection process shown in FIG. 4B. The resolution is reduced from 600 dpi to 150 dpi so that the inspection process can be performed within the printing speed. Note that if the CPU 238 is fast enough to perform the inspection process at high resolution within the printing speed, this resolution conversion is unnecessary. Next, the process proceeds to S314, where the CPU 238 aligns the inspection target image data with the reference image and performs image correction (alignment) so that the inspection target image data can be compared to check for any defects (such as dirt or dust) that are not present in the reference image. The purpose of this image correction is to determine correction values ​​for the skew and scaling, since the inspection target image data obtained by scanning the printed material is slightly curved or scaled due to factors such as paper transportability, so that it can be compared with a reference image that is free of skew or scaling. The process then proceeds to S315, where the CPU 238 compares the inspection target image data that has been image-corrected in S314 with the reference image, performs inspection processing to check for dirt, dust, etc., and determines the inspection results for each page. The process then proceeds to S316, where the CPU 238 controls the printouts that pass inspection based on the results of the inspection processing to be sent to the finisher 111, and selects an output tray for the printouts that fail inspection, so that they are discharged to the purge tray of the stacker 110, and proceeds to S317.

[0052] In S317, the CPU 238 determines whether the character quality adjustment 402 is set to ON. If the character quality adjustment 402 is ON, the process proceeds to S318; if not, the process proceeds to S323. In S318, the CPU 238 extracts the character portion from the inspection target image data and the reference image stored in the HDD 255 based on the coordinates of the character portion determined in S305. While resolution conversion was performed in the inspection process described above, resolution conversion is not performed in the character quality inspection process because the characters are processed at a high resolution. Because the characters are present only in part of the page and are small in size, high resolution does not have much impact on processing speed.

[0053] FIG. 8 shows an example of an image in which the character portion has been cut out from the reference image. FIG. 9(A) shows an example of an image in which the character portion has been cut out from the image to be inspected. The reference image is a rendering image and is therefore not curved, so it is cut out at the specified character drawing position. In contrast, the image data to be inspected is obtained by scanning a printed material, so it is often curved as shown in FIG. 9(A). Therefore, a range larger than the specified character drawing position is cut out from the image data to be inspected. Details of character extraction will be explained in the character portion coordinate analysis section.

[0054] Next, the process proceeds to S319, where the CPU 238 aligns the inspection object image data with the reference image. Here, image correction (alignment) is performed so that the inspection object image data can be compared with the reference image to check for thickening or thinning of characters. An example of an image in which the character portion cut out from the inspection object image data has been corrected is shown in FIG. 9(B). This is a diagram showing an example in which the rotation of the characters shown in FIG. 9(A) has been corrected.

[0055] Next, the process proceeds to S320, where the CPU 238 compares the inspection target image data corrected in S319 with the reference image to inspect the character quality, such as whether the character lines are thick or thin, and obtains the inspection result, a character thickness degree α, which indicates the thickness or thinness of the lines, for each page. Details of this inspection will be described later in the section on character adjustment control.

[0056] Next, proceeding to S321, the CPU 238 determines whether to apply the inspection result of S320 to the adjustment control of the character quality of the image processing unit 224 of the printing apparatus 107. Here, since the characters are fine and include the variations of the printing unit 226, the average of the character boldness α for 100 pages is taken so that the average value can be applied to the character quality adjustment for every 100 pages. That is, it is determined whether it is the 100th page. If it is the 100th page, it is determined to apply the adjustment and proceed to S322. Otherwise, it proceeds to S323. Here, the average for 100 pages is obtained, but the number of pages may be changed according to the variations of the printing unit 226. Also, in the case of a job within 100 pages, the average of the pages of the job is taken, and finally the average is applied, etc., and it may be changed according to the situation of the job. In S322, the CPU 238 sets to apply the inspection result to the adjustment control of the character quality of the image processing unit 224 of the printing apparatus 107. The details of the adjustment control of the character quality will be described later. In S323, the CPU 238 determines whether the inspection process and the character quality inspection for all pages have ended. If they have ended, this process ends. If they have not ended, it proceeds to S303 to process the next page.

[0057] Note that in S322, the inspection result may be notified to the external controller 102, and the print data may be adjusted by the external controller 102.

[0058] Next, an explanation regarding the details of the analysis of the coordinates of the character portion performed in the PDL interpretation process of S303 will be given.

[0059] First, the coordinate analysis of the character portion is performed. Regarding the characters, it is preset in the character quality inspection setting screen of FIG. 5(A). FIG. 5(A) is an example of the character quality inspection setting screen. Instead of one character, all the characters used in the page are inspected, and there is no problem in correcting based on the inspection result. In FIG. 5(A), the resolution is 600 dpi, the font size is 7 points or less, and the character font is set to the Chinese character '情' of the font type KozMinProN - Gegular.

[0060] FIG. 6 is a diagram for explaining an example of print data (printed matter) printed on a sheet 601 according to the above-described settings in Embodiment 1. Here, only the Chinese character "情" is printed.

[0061] In the figure, 602 indicates the printed Chinese character "情". The left margin 604 of the Chinese character 602 is 416 pixels at 50 points, and the length 605 from the bottom is 6000 pixels at 720 points. Therefore, the upper left coordinates (x1, y1) of the Chinese character 602 are (416, 6000). Also, since the character size is 5 points, it is 41 pixels wide, and the lower right coordinates (x2, y2) are (457, 6041). Also, since the inspection target image may be curved, as shown in FIG. 8, a margin of 30 pixels is provided, and the cutout range of the character is set to (x3, y3) = (386, 6030) and (x4, y4) = (487, 6071). Note that this margin may be a value according to the performance of the printer, and 30 of the margin is an example.

[0062] FIG. 8 is an enlarged view of the cutout range of this character.

[0063] Here, an example is shown in which print data of the Chinese character "情" specified in the KozMinPr6N-Regular font with a font size of 5 points is printed. FIG. 7 is a diagram showing an example of the PDL data PDF description of the printed matter in FIG. 6. Hereinafter, character coordinate analysis will be described with reference to FIGS. 6 to 9 and FIG. 13.

[0064] FIG. 13 is a flowchart for explaining the coordinate analysis process of the character part executed by the external controller 102 according to Embodiment 1. Note that the process shown in this flowchart is achieved by the CPU 208 of the external controller 102 executing a program developed in the memory 209.

[0065] First, in S1301, the CPU 208 obtains the font type, font size, and font settings used for the character quality inspection that are preset on the character quality inspection setting screen in FIG. 5(A). Here, as an example, the font is the Chinese character "情" (character code 8fee), the font size is 7 points (pt) or less, and the font type is KozMinPr6N-Regular. This is just an example, and it is not limited to this as long as it is a font for which inspection for character quality adjustment is possible. In the character quality inspection, it is desirable that the character to be inspected includes a portion with a thin line width and a portion where it is possible to determine whether the line width is thicker or thinner compared to the reference image.

[0066] Next, proceeding to S1302, the CPU 208 determines in the font type specification section 701 of the PDL data shown in FIG. 7 whether the description of / Type / Font is the set font type "KozMinPr6N-Regular". If it is the set font type, it proceeds to S1303, but if not, this process ends. Here, since KozMinPr6N-Regular is described, it proceeds to S1303.

[0067] In S1303, the CPU 208 determines whether the font code "8fee" corresponding to the Chinese character "情" set in the font specification section 702 of the PDL data shown in FIG. 7 is used for the description of / F0. If the specified font code is described, the process proceeds to S1304; otherwise, the process ends. Here, since the font code "8fee" is used, the process proceeds to S1304. In S1304, the CPU 208 determines whether 7 pt or less of the set font is used for the description of / F0 in the font specification section 702 of the PDL data shown in FIG. 7. If 7 pt or less of the set font is used, the process proceeds to S1305; otherwise, the process ends. Here, 5 pt is used and it is 7 or less, so the process proceeds to S1305. In S1305, the CPU 208 obtains the upper left coordinates (x1, y1) of the rectangle of the character from the description of "1.0.0.1.50.770.cm" in the font specification section 702 of the PDL data in FIG. 7. These numbers indicate that "1.0.0.1." represents a square matrix and there is no rotation, and "50.770." indicates a translation of 50 points to the right and 72 * 10 points upward. That is, at 600 dpi, the left margin 604 is 50 points or 416 pixels, the vertical length is 72 * 10 points or 6000 pixels, and the upper left coordinates (x1, y1) of the Chinese character 602 are (416, 6000). Since the size of the Chinese character 602 here is 5 pt, it is 41 pixels, and the lower right coordinates (x2, y2) of the Chinese character 602 are (457, 6041). Also, since the inspection target image may be curved, a margin of 30 pixels is provided, and the range of the character is set as (x3, y3) = (386, 6030) and (x4, y4) = (487, 6071).

[0068] Next, the details of the quantification of characters and the details of the image processing for character quality adjustment will be described.

[0069] The CPU 238 quantifies the character quality. First, in S319, the differential data between the aligned reference image and the inspection target image is generated. Specifically, for each pixel at the same position in the reference image and the inspection target image, the difference value of the pixel values is calculated. The difference is calculated by the following formula.

[0070] Difference value = (pixel value of character in inspection image) - (pixel value of character in reference image) 10(D) to 10(F) are schematic diagrams for explaining the quantification of character image quality.

[0071] Fig. 10(D) is an enlarged view of a portion 801 of the reference character image in Fig. 8, and Fig. 10(E) is an enlarged view of a portion 901 of the test character image in Fig. 9(B). Pure black pixels represent the character portion. Here, to simplify the explanation, a binarized image (pure white 255, pure black 0) is used, but a color image with 8 bits for each RGB color can also be used as is.

[0072] Figure 10(F) shows the difference data calculated from Figure 10(D) and Figure 10(E). Pure black pixels have a difference value of 0, pure white pixels have a difference value of 255, and diagonally shaded pixels have a difference value of "-255."

[0073] Next, the amount of character thickening in the printed material is calculated based on this difference data. First, the number of pixels N1 where the negative difference value in the difference data is less than a predetermined negative threshold (th1) is calculated. Next, the number of pixels N2 where the positive difference value is greater than a predetermined positive threshold (th2) is calculated. Then, the character thickening degree α is calculated from the ratio of the difference between the pixel counts of N1 and N2 (N1-N2) to the number of pixels in the character part of the image being inspected.

[0074] α = (N1-N2) / (number of pixels in the character part of the image to be inspected) For example, in the case of the differential data shown in FIG. 10(F), if th1 and th2 are both set to 0 for simplicity, N1 becomes 1 and N2 becomes 8. Therefore, the value of the character thickness degree α in FIG. 10(E) is calculated using the above-mentioned formula as follows: α = (1 - 8) / 30 ≒ -0.23 Although a portion of a character is used here for the purpose of explanation, in practice the same calculation is performed on the entire character.

[0075] For example, in Figures 10(A) to 10(C), Figure 10(A) shows a reference image, Figure 10(B) shows the image to be inspected, and Figure 10(C) shows the difference image. In this way, the difference is calculated for the entire character, not just a part of the character, and the character thickness is calculated from that difference. Through the above process, the character characteristics can be quantified using the character thickness α.

[0076] If the character thickness degree α is a positive value, the character is determined to be thick, and the adjustment amount is changed to thin the character. On the other hand, if the character thickness degree α is a negative value, the character is determined to be thin, and the adjustment amount is changed to thicken the character. In this way, character quality adjustment control is performed based on the character thickness degree α. First, an adjustment level Lc is determined based on the character thickness degree α. This adjustment level Lc is determined by referring to a table that is prepared in advance and associates the character thickness degree α with the adjustment amount, for example.

[0077] FIG. 11 is a diagram showing an example of a table showing the relationship between the character thickness degree α and the adjustment level Lc.

[0078] For example, in the case of Fig. 10(C), the determined character thickness α is α≈-0.23, and therefore, referring to Fig. 11, the adjustment level Lc can be determined to be +1. After determining the adjustment level Lc in this way, the inspection device 109 feeds back the determined adjustment level Lc to the printing device 107. As a result, from the next rendering process onwards, the image processing unit 224 of the printing device 107 can perform character quality adjustment processing using the adjustment level Lc, thereby enabling adjustment control of character quality.

[0079] An example of text image quality adjustment in the image processing unit 224 using the adjustment level Lc will now be described with reference to FIG.

[0080] FIG. 12 is a diagram illustrating adjustment control of character quality by the image processing unit 224 of the printing device 107 according to the first embodiment.

[0081] Figures 12(A), (B), (D), and (E) show images obtained by adjusting the image in Figure 12(C) according to the adjustment level Lc. Figure 12(A) shows a line narrowed by 1 (=0.5 x 2) pixel width at an adjustment level of "-2." Figure 12(B) shows a line narrowed by 0.5 (=0.5 x 1) pixel width at an adjustment level of "-1." Figure 12(D) shows a line widened by 0.5 (=0.5 x 1) pixel width at an adjustment level of "+1." Figure 12(E) shows an image of a line widened by 1 (=0.5 x 2) pixel width at an adjustment level of "+2."

[0082] As shown in Figures 12(A) and (E), the adjustment to narrow or widen the width by one pixel is performed by thinning out or adding one pixel to all pixels on one side of the image portion indicating the line width of the input image, the line width image of Figure 12(C).

[0083] Next, the adjustment to narrow or widen the line width by 0.5 pixels is performed by thinning or adding every other pixel on one side of the image portion showing the line width to the input image, the line width image of FIG. 12(C), as shown in FIG. 12(B) and (D).

[0084] As described above, according to the first embodiment, the inspection process for printed matter and the inspection for adjusting character quality are performed using the same inspection device, so the system does not become large, and there is no need to reserve a large space for installing the system. Furthermore, by performing these processes using a single inspection device, the system control does not become complicated, various settings and operations by the user are simplified, and work becomes more efficient.

[0085] [Embodiment 2] In the first embodiment, the settings for character quality inspection were made by specifying the font type, size, and font on the screen shown in Fig. 5(A). In contrast, in the second embodiment, the settings are made without specifying the font type, size, and font. Note that the system configuration and hardware configurations of the various devices according to the second embodiment are the same as those of the first embodiment, and therefore a description thereof will be omitted.

[0086] In the second embodiment, the operation will be described when all the setting items for character quality inspection are set to automatic, as shown on the setting screen in FIG. 5(B).

[0087] Fig. 14 is a flowchart illustrating the processing flow in the printing system according to the second embodiment, and is a flowchart illustrating the processing up to printing in S307 in Fig. 3. Note that the same reference numerals are used to denote the same processes as in Fig. 3, and descriptions thereof will be omitted.

[0088] In S304, the CPU 208 of the external controller 102 determines whether the character quality adjustment 402 was set to ON in S301. If the character quality adjustment 402 is set to ON, the process proceeds to S1401, where the CPU 208 analyzes the character specifications of the PDL commands in the print data for each page based on the interpretation of the PDL, and automatically selects a character type to be used for inspecting character quality. Here, when interpreting the PDL, the character specifications of the PDL commands used within the page are analyzed. For example, since Gothic fonts are more likely to cause character distortion, a character type with Gothic in its font type name is selected. Furthermore, since Mincho fonts are more likely to cause character blurring, a character type with Mincho in its font type name is selected. Since the smaller the font size, the more likely it is that distortion and character blurring will occur, the smallest character type among the fonts used is selected. Furthermore, since the more strokes a character has, the finer the lines, a character type with the most strokes is selected. These are merely examples of character type selection; a frequently used and highly noticeable character type may also be selected. It should be noted that the resolution can be set to the maximum resolution during rendering if the resolution used for rendering during printing is used.

[0089] Then, the process proceeds to S305, where the CPU 208 of the external controller 102 obtains the coordinates of each character portion of the character selected in S1401. The coordinate values ​​obtained here can be used when inspecting character quality.

[0090] As described above, according to the second embodiment, by automating the character and font settings in the character quality inspection settings, the user's settings and work are automated, saving time and effort and enabling efficient work.

[0091] [Embodiment 3] In the second embodiment, the smallest character type among the font sizes used was selected. In contrast, in the third embodiment, in order to further improve the accuracy of character inspection, the font is actually rendered and drawn. Fonts that include areas that are particularly prone to thinning, blurring, and interruptions are extracted, and these fonts are registered as fonts for character inspection, and character inspection is then performed. Note that the system configuration and hardware configurations of various devices according to the third embodiment are the same as those of the first and second embodiments, and therefore a description thereof will be omitted.

[0092] As with the second embodiment, the third embodiment is an embodiment of the operation when all setting items for character quality inspection are set to automatic, as shown on the setting screen in FIG. 5(B).

[0093] 15 is a flowchart illustrating the flow of image quality inspection font setting registration processing by the external controller 102 of the printing system according to the third embodiment. Based on the image quality inspection font setting registration shown in this flowchart, the image quality inspection font setting is acquired in S1301 of Fig. 13. The processing shown in this flowchart is realized by the CPU 208 of the external controller 102 executing a program loaded in the memory 209.

[0094] First, in S1501, the CPU 208 performs PDL interpretation on the PDL data. Next, the process proceeds to S1502, where the CPU 208 obtains font settings from the PDL data during PDL interpretation. For example, an example will be described in which the font character is "a," the font size is 6 points (pt), and the font type is Times New Roman.

[0095] Next, the process proceeds to S1503, where the CPU 208 renders the font acquired in S1502 at a pre-specified resolution and converts it into a bitmap image.

[0096] FIG. 16 is a diagram showing an example of development of a character font according to the third embodiment.

[0097] Figure 16(A) shows the font for the letter "a." Figure 16(B) shows the bitmap image of the letter "a" after it has been rendered at a resolution of 600 dpi. Font rendering is done in a binary way, determining which pixels are painted and which pixels are not. Therefore, as shown in Figure 16(B), it can be seen that the curved parts are uneven compared to Figure 16(A). Also, one pixel in Figure 16(B) represents one pixel at 600 dpi. As can be seen from Figure 16(B), the bitmap image of this character is one continuous block.

[0098] Next, the process proceeds to S1504, where the CPU 208 performs anti-aliasing to reduce the jaggedness at the pixel level at a resolution of 600 dpi, so that the image looks closer to that shown in FIG. 16(A). FIG. 16(C) shows the image after anti-aliasing. Anti-aliasing is a process that applies a neutral color to jagged areas to artificially reduce the jaggedness and make curved areas look smoother, and is usually added when printing text. In other words, the image that is actually printed is the image shown in FIG. 16(C), not FIG. 16(B).

[0099] Therefore, in order to improve the accuracy of detecting thinning, blurring, and breaks, it is necessary to set an inspection font that detects thinning, blurring, and breaks in the anti-aliased image, even though the speed will be reduced by the amount of anti-aliasing processing. For example, in Figure 16(B), pixels 1601 and 1602 are black pixels. However, pixels 1603 and 1604, which correspond to pixels 1601 and 1602 after anti-aliasing, are halftone. Therefore, the color of the character in that area will be lighter, and there is a possibility that the line will be broken. Therefore, it is necessary to register the font of the image "a" after anti-aliasing as an inspection font for detecting thinning, blurring, and breaks.

[0100] Next, the process proceeds to S1505, and the CPU 208 performs binarization processing on the image data that has undergone anti-aliasing processing, since determination cannot be easily made in the halftone state shown in FIG. 16C.

[0101] FIG. 17 is a diagram showing an example of an image obtained by applying binarization processing to image data that has been subjected to anti-aliasing processing.

[0102] The process then proceeds to S1506, where the CPU 208 determines that the portion of the image data after anti-aliasing in Fig. 17 where discontinuities have occurred is blurred, discontinuous, etc. from the image without discontinuities after rendering in Fig. 16(B). Here, the portions indicated by 1701 and 1702 in Fig. 17 are detected as discontinuities.

[0103] 16(B) and 17, the presence or absence of line fading or thinning can be determined from the amount of reduction in the number of black pixels by utilizing the fact that the font is thinner. This determination method is not limited to the process described in the third embodiment, and any method can be used as long as it can determine whether or not there is line fading or thinning.

[0104] If the CPU 208 determines in S1506 that there is fading or discontinuities in the lines, the process proceeds to S1507; if it determines that there is no fading or discontinuities, the process proceeds to S1508. In S1507, the CPU 208 sets and registers the font character "a," the font size to 6 points (pt), and the font type to Times New Roman as the font for image quality inspection. When the font registered in this way is used in PDL data, the coordinate position of the font is analyzed, and character quality is adjusted based on the analysis results, as described in the first embodiment.

[0105] The process then proceeds to step S1508, where the CPU 208 checks whether the fonts used in the PDL data have been checked. If so, the process ends. If it is determined that the fonts have not been checked, the process proceeds to step S1502, where the next font is acquired. Because there are many different types of fonts, the process of acquiring fonts may be repeated, starting with small point sizes, as was done in the automation of the second embodiment, and ending once multiple test fonts have been registered. Also, if a font does not have small point sizes and is sufficiently thick, it may not be registered as a test font, and if it is not registered, character inspection and adjustment may not be performed.

[0106] In the third embodiment, blurring and breaks in lines are determined by comparing a rendering image with an anti-aliased image. Also, by determining the image to which edge processing of the digital registration correction process, which is performed during printing, it becomes possible to detect breaks in thin lines caused by steps when switching the registration, which has the effect of improving accuracy, just like anti-aliasing.

[0107] As described above, according to the third embodiment, fonts for character inspection are extracted using not only a rendering image but also an image after edge processing such as an anti-aliased image. This makes it possible to reliably extract characters that may have thinned, blurred, or broken lines.

[0108] (Other embodiments) The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0109] The disclosure of this specification includes the following inspection apparatus, control method thereof, printing system, and program.

[0110] [Item 1] An inspection device for inspecting printed matter, a reading means for reading a printed matter and acquiring image data of an object to be inspected; an inspection means for performing inspection processing of the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when an inspection processing for inspecting defects of the printed matter is set; a character quality inspection means for performing character quality inspection processing of the image data to be inspected, which is obtained by reading the printed matter with the reading means, based on a reference image, when a character quality inspection processing for inspecting the quality of characters on the printed matter is set; an instruction means for instructing the printing device that generated the printed matter to adjust image data to be printed in accordance with the inspection result by the character quality inspection means; An inspection device comprising:

[0111] [Item 2] The inspection device described in item 1, characterized in that the reference image used by the inspection means and the reference image used by the character quality inspection means are images based on PDL (Printer Description Language) data used for the reference image.

[0112] [Item 3] The inspection device further includes a resolution conversion unit that converts the resolution of the image data of the inspection object and the reference image used by the inspection device, 3. The inspection device according to item 1 or 2, wherein the resolution conversion means converts the image data of the inspection object and the reference image used by the character quality inspection means into a resolution lower than the resolutions of the image data and the reference image.

[0113] [Item 4] The inspection device described in any one of items 1 to 3, characterized in that the character quality inspection means automatically determines the character type to be used for inspecting the character quality contained in the image data to be inspected, based on the PDL data used for the reference image.

[0114] [Item 5] 5. The inspection device according to item 4, wherein the determination of the character type is made using image data in which edge processing has been applied to image data of the characters included in the printed matter.

[0115] [Item 6] 6. The inspection device according to item 5, wherein the image data to which the edge processing has been applied is image data that has been subjected to anti-aliasing processing.

[0116] [Item 7] 6. The inspection device according to item 5, wherein the image data to which the edge processing has been applied is image data that has been subjected to digital registration correction processing.

[0117] [Item 8] 8. The inspection device according to any one of items 1 to 7, further comprising a setting means for setting the inspection process, the character quality inspection process, or both the inspection process and the character quality inspection process.

[0118] [Item 9] Item 9. The inspection device according to item 8, wherein the setting means can set the resolution of the image data of the inspection object and the reference image used by the inspection means, and the resolution of the image data of the inspection object and the reference image used by the character quality inspection means.

[0119] [Item 10] 10. The inspection device according to item 8 or 9, wherein the settings for the character quality inspection process include the type of character to be inspected.

[0120] [Item 11] The character quality inspection device described in any one of items 1 to 10 is characterized in that the character quality inspection means extracts the character to be inspected from the image data of the inspection object and the reference image to be used, and obtains a character thickness indicating the thickening or thinning of the line width of the extracted character, and the indication means indicates the amount of adjustment for the adjustment according to the character thickness.

[0121] [Item 12] Item 12. The inspection device according to item 11, wherein the degree of character thickening is determined based on the difference between the number of negative pixels and the number of positive pixels in the differential data of pixel values ​​of the character part of the inspection target in the image data of the inspection target and the character part of the inspection target in the reference image relative to the number of pixels of the character part of the inspection target in the reference image.

[0122] [Item 13] A printing system including an information processing device that transmits print data to a printing device to print it, a printing device that executes printing based on the print data to generate a printed matter, and an inspection device according to any one of items 1 to 12, the printing device or the information processing device transmits image data to the inspection device, the image data being the reference image generated from the print data; A printing system characterized in that the instruction means of the inspection device issues an instruction for the adjustment to the printing device or the information processing device.

[0123] [Item 14] Item 14. The printing system according to item 13, wherein the inspection device further comprises a setting means for setting the inspection process, the character quality inspection process, or both the inspection process and the character quality inspection process.

[0124] [Item 15] the inspection device further comprises a resolution conversion means for converting the resolution of the image data of the inspection object and the reference image used by the inspection means, 15. The printing system according to item 13 or 14, wherein the resolution conversion means converts the image data of the inspection object and the reference image used by the character quality inspection means into a resolution lower than the resolution of the image data.

[0125] [Item 16] A control method for controlling an inspection device that inspects printed matter, the inspection device having a reading means that reads printed matter and acquires image data of the inspection target, comprising: an inspection step for performing inspection processing of the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when an inspection processing for inspecting defects of the printed matter is set; a character quality inspection step for performing character quality inspection processing on the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when a character quality inspection processing for inspecting the quality of characters on the printed matter is set; an instruction step of instructing the printing device that generated the printed matter to adjust image data to be printed in accordance with the inspection result of the character quality inspection step; A control method comprising:

[0126] [Item 17] A program for causing a computer to execute each step of the control method described in Item 16.

[0127] The present invention is not limited to the above-described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to apprise the public of the scope of the present invention. [Explanation of symbols]

[0128] 101...printing system, 102...external controller, 103...client PC, 107...printing device, 109...inspection device, 224...image processing unit, 240...image reading unit

Claims

1. An inspection device for inspecting printed matter, a reading means for reading a printed matter and acquiring image data of an object to be inspected; an inspection means for performing inspection processing of the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when an inspection processing for inspecting abnormalities in the printed matter is set; a character quality inspection means for performing character quality inspection processing of the image data to be inspected, which is obtained by reading the printed matter with the reading means, based on a reference image, when a character quality inspection processing for inspecting the quality of characters on the printed matter is set; an instruction means for instructing the printing device that generated the printed matter to adjust image data to be printed in accordance with the inspection result by the character quality inspection means; An inspection device comprising:

2. 2. The inspection device according to claim 1, wherein the reference image used by the inspection means and the reference image used by the character quality inspection means are images based on PDL (Printer Description Language) data used for the reference image.

3. The inspection device further includes a resolution conversion unit that converts the resolution of the image data of the inspection object and the reference image used by the inspection device, The inspection device described in claim 1, characterized in that the resolution conversion means converts the resolution of the image data of the inspection object and the reference image used in the inspection process to a resolution lower than the resolution of the image data of the inspection object and the reference image used by the character quality inspection means.

4. The inspection device according to claim 1, characterized in that the character quality inspection means automatically determines the character type to be used for inspecting the character quality contained in the image data to be inspected based on the PDL data used for the reference image.

5. 5. The inspection device according to claim 4, wherein the character type is determined using image data in which edge processing has been applied to image data of the characters included in the printed matter.

6. 6. The inspection apparatus according to claim 5, wherein the image data to which the edge processing has been applied is image data that has been subjected to anti-aliasing processing.

7. 6. The inspection apparatus according to claim 5, wherein the image data to which the edge processing has been applied is image data that has been subjected to digital registration correction processing.

8. 2. The inspection device according to claim 1, further comprising a setting unit for setting the inspection process, the character quality inspection process, or both the inspection process and the character quality inspection process.

9. The inspection device according to claim 8, characterized in that the setting means can set the resolution of the image data of the inspection object and the reference image used by the inspection means, and the resolution of the image data of the inspection object and the reference image used by the character quality inspection means.

10. 9. The inspection device according to claim 8, wherein the settings for the character quality inspection process include a character type to be inspected.

11. The inspection device according to claim 1, characterized in that the character quality inspection means extracts the character to be inspected from the image data of the inspection object and the reference image to be used, calculates a character thickness indicating the thickening or thinning of the line width of the extracted character, and the indication means indicates the amount of adjustment for the adjustment according to the character thickness.

12. The inspection device according to claim 11, characterized in that the degree of character thickening is determined based on the difference between the number of negative pixels and the number of positive pixels in the differential data of pixel values ​​of the character part of the inspection target image and the image data of the inspection target image relative to the number of pixels of the character part of the inspection target image.

13. A printing system including an information processing device that transmits print data to a printing device to cause printing, a printing device that executes printing based on the print data to generate a printed matter, and an inspection device, The inspection device includes: Scan the printed material to obtain image data of the object to be inspected, When an inspection process for inspecting an abnormality in the printed matter is set, the inspection process is performed on the image data of the inspection object obtained by reading the printed matter based on a reference image; When a character quality inspection process for inspecting the quality of characters on the printed matter is set, the character quality inspection process is performed on the image data of the inspection target obtained by reading the printed matter based on a reference image; instructing the printing device that generated the printed material to adjust image data to be printed according to the inspection result of the character quality inspection process; the printing device or the information processing device transmits image data to the inspection device, the image data being the reference image generated from the print data; The printing system is characterized in that the instruction for the adjustment is given to the printing device or the information processing device.

14. 14. The printing system according to claim 13, wherein the inspection device further comprises a setting unit for setting the inspection process, the character quality inspection process, or both the inspection process and the character quality inspection process.

15. the inspection device further comprises a resolution conversion means for converting the resolution of the image data of the inspection object and the reference image used in the inspection process; The printing system described in claim 13, characterized in that the resolution conversion means converts the resolution of the image data of the inspection object and the reference image used in the inspection process to a resolution lower than the resolution of the image data of the inspection object and the reference image used in the character quality inspection process.

16. An inspection device for inspecting a printed matter printed by a printing device, comprising: an acquisition means for acquiring image data of the inspection object obtained by reading a printout printed on a recording sheet based on the reference image data with a reading unit; an inspection means for inspecting whether or not there is a point abnormality in the image data of the inspection object based on the reference image data; an instruction means for instructing the printing device to adjust printing conditions based on a difference between an object extracted from the reference image data and an object extracted from the image data of the inspection target corresponding to the object; An inspection device comprising:

17. The image processing device further comprises a resolution conversion means for converting the resolution of the reference image data, 17. The inspection apparatus according to claim 16, wherein the inspection means inspects the image data of the inspection object based on image data obtained by converting the reference image data to a lower resolution by the resolution conversion means.

18. The object is a character, The inspection device according to claim 16, further comprising a setting means for setting the process of inspecting for the presence of dot-like abnormalities or the process of determining character quality, or both the process of inspecting for the presence of dot-like abnormalities and the process of determining character quality.

19. The inspection device described in Claim 16, further characterized in that it has a judgment means for judging the quality of an object extracted from an area of ​​the image data of the inspection target excluding at least the areas of the inspected image data of the inspection target where point-like abnormalities exist.

20. A control method for controlling an inspection device that inspects printed matter, the inspection device having a reading means that reads printed matter and acquires image data of the inspection target, comprising: an inspection step for performing inspection processing of the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when an inspection processing for inspecting the printed matter for abnormalities is set; a character quality inspection step for performing character quality inspection processing on the image data of the inspection target obtained by reading the printed matter with the reading means based on a reference image when a character quality inspection processing for inspecting the quality of characters on the printed matter is set; an instruction step of instructing the printing device that generated the printed matter to adjust image data to be printed in accordance with the inspection result of the character quality inspection step; A control method comprising:

21. A program for causing a computer to execute each step of the control method according to claim 20.

Images